Retractable landing gear for aeroplanes



R. L. LEVY July 5, 1938.

RETRACTABLE LANDING GEAR FOR AEROFLANES Filed Jan. 9, 1936 3 Sheets-Sheet 1 July 5,1938. R. LEVY RETRACTABLE LANDIINGVGEAR FOR AEROPLANES a Shets-Sheet 2 Filed Jan. 9. 1936 July 5, 1938. R. L. LEVY RETRACTABLE LANDING GEAR Fox AEROPLANES Filed Jan. 9. 1936 l s sheets-sneak 3 Patented July 5, 1938 RETRACTABLE LANDING GEAR FOR AERO- PLANES Rene Lucien ilvy, Montrouge, France, assignor to Socit dinventions Aronautiques et Mcaniques, S. I. A. M., Fribourg', Switzerland Application January 9, 1936, Serial No. 58,39 'l In France February 4, 1935 1 Claim.

It is known that, in some forms of retractable landing gear for aeroplanes completely to withdraw each wheel into a housing in a. wing such that, in order to reach the housing, the wheel,-in

on the supporting leg J. The joints and g which should possess at least two degrees of freedom, will be in the form for example, of ball joints.

being raised from its lowered position, has to The actuating members for raising or lowering describe a movement towards the rear-or tothe gear may-if the relative arrangement of the wards the iront,-sometimes even in an oblique several members of the articulated system perdirection in relation to the median plane of the mitsbe combined in a single jack of the doubleaeroplane. acting type, that is one which works in both Known solutionsthe application of which, directions.

however, is far from being satisfactory in all the AS in the typ C se Selected, there y also cases on account of the diversity of structure of be provided, for lowering the gear, a single actthe numerous types of aeroplanes-'-consist in ing jack V, pivotally mounted, on the one hand, displacing the wheel either about an obliquely on the axis of the rod, 12 b and, on the other, at

directed axis, or about. two axes. In the latter a point e on the leg J. The raising is efiected by case, the raising is effected in two successive stages, for example, at first by a rotational movement towards the rear, and then by a lateral rotation-and vice versa for lowering.

The object of the present invention is a re-' .tractable wheel assembly in which the wheel describes two rotational movements about two distinct axes, but is characterized substantially-by comparison with the above mentioned systemsin that the two rotations are combined and proceed simultaneously, the resultant movement being determined entirely by the presence of a member-bar or the like, of constant length,

which maintains a continuous connection between a fixed point on the aeroplane and a suitably selected point on the leg, or similar mobile member, supporting the wheel.

In the accompanying drawings, Figures 1 to 3 and Figures 4 to 6 represent respectively two embodiments of such retractable gear according to the present invention, Figure 1 being a front elevation of a. first embodiment, Figure 2 being a corresponding plan and Figure 3 a side elevation thereof, whilst Figure 4 is a Iront elevation of a second embodiment, Figure 5 a plan thereof,

40 showing the wheel in the retracted position, and

Figure 6 a slde'elevation showing the wheel in the lowered position.

Referring to Figures 1-3; the wheel R is carried by a cushioning leg J, constituted for example, in the form of an oleopneumatic shock absorbet.

The upper part of the leg J is bifurcated as at p and pivoted on the aeroplane by a spindle a a. carried. in turn, by a rod b b the axis of which, in this example, is perpendicular to that of the former.

The path of the wheel in passing from the lowered position R to the retracted position R.

85 is determined completely by the presence of a bar K, of constant length, plvotally mounted on the one hand, at'a fixed point c-which, in the example shown, is on one or the longrons of the wing-and, on the other hand, at a point a a second jack T, pivoted on a fixed point k and acting on the end of a crank m, keyed on the rod bb. In the position T, said jack T also serves to maintain the wheel in the raised position R.

In the figures, the reference characters showing the position of the various members when raised, are distinguished by the index i. Moreover, for the sake of clarity, certain members are represented solely by their axial line.

Figures 4 to 6 represent another embodiment of the invention. They relate to an example in which the shock absorber A, mounted on the wheel R, forms part of a'pivotal triangular support A-J-B (Figure 6). The leg J- -on which the link B and shock absorber A are, pivoted at d and J respectively-is the equivalent of the member J in the previous example. The members described in relation to this latter are shown-with the same reference characters-in Figures 4 to 6, and particularly the bar K, of constant length, which determines the path of the leg J, movable about two axes M and b-b, that is to say, the characteristic combination of the invention.

What I claim as my invention and desire to secure byI-etters Patent is:

Retractable landing gear for aeroplanes, comprising, a wheel, a first element constituted by a leg supporting the wheel, two separate axes intersecting at a fixed point and around which the supporting leg is adapted to pivot, a. second element constituted by a directing bar of constant length connected to a iixed point of the aeroplane and to a point of the supporting leg, a third element constituted by a Jack pivoted on the one hand at a point on one of the oscillating axes of the supporting leg and on the other hand at a. point of the said leg, a second jack pivoted on the one hand at a fixed point of the aeroplane and on the other hand on a crank keyed on the RENE LUCIEN LEVY.

. said oscillating axis. 

